C45R vs S355M: 38% composition overlap. Significantly different materials serving different application areas.
C45R vs S355M
Side-by-side chemical composition and mechanical property comparison.
Overview
C45R
1.1201
Unalloyed special steel with controlled sulfur (R grade, S 0.020–0.040%) and 0.45% carbon for improved machinability. Same base composition as C45E but with intentional sulfur for better chip formation. The most popular R-grade carbon steel for high-volume automated machining. Used for axles, bolts, connecting rods, spindles, crankshafts, and general machine parts.
S355M
1.8823
Thermomechanically rolled weldable fine-grained structural steel with minimum yield strength 355 MPa. The most widely used TMCP structural steel grade. M designation indicates thermo-mechanical control process delivery. Excellent weldability with low carbon equivalent, eliminating preheating in most cases. Used for bridges, offshore structures, cranes, heavy machinery, wind turbine foundations, and structural hollow sections.
| C45R | S355M | |
|---|---|---|
| Material Number | 1.1201 | 1.8823 |
| Category | Carbon Steel | Carbon Steel |
| Standard | EN 10083-2 | EN 10025-4 |
Chemical composition (wt%)
| Element | C45R | S355M | Overlap |
|---|---|---|---|
| C | 0.42–0.5% | ≤ 0.16% | No overlap |
| Si | ≤ 0.4% | ≤ 0.55% | OK |
| Mn | 0.5–0.8% | ≤ 1.6% | OK |
| P | ≤ 0.025% | ≤ 0.035% | OK |
Mechanical properties
| Property | C45R | S355M | Unit |
|---|---|---|---|
| tensile_strength | 580–730 | 450–610 | MPa |
| yield_strength | ≥ 305 | ≥ 355 | MPa |
| elongation | ≥ 16 | ≥ 22 | % |
Compatibility Assessment
C45R and S355M have significantly different compositions (38% overlap). These materials are not interchangeable and serve different application areas.
Automated assessment based on composition analysis
Frequently Asked Questions
Is C45R the same as S355M?
C45R and S355M have a 38% composition overlap. They are generally not directly interchangeable.
Can I replace C45R with S355M?
Generally not recommended. The compositions differ significantly (38% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between C45R and S355M?
The main differences are in the following elements: C, S. C45R is a Carbon Steel grade, while S355M is a Carbon Steel grade.
View full data for each material:
Data provided for reference only. Always verify against the applicable specification for critical applications.
All data is for reference only. Equivalents indicate similarity, not identity. Always verify against the applicable specification for safety-critical applications. materialref.com accepts no liability for decisions based on this data.